Patent GB-854256-A (GB)
Title: Tire building machine and method
IPC: B23B39/04
Filed: 1959-03-17
Abstract: 854,256. Tyre-building apparatus. NATIONAL-STANDARD CO. March 17, 1959 [April 23, 1958], No. 9234/59 Class 144 (1). Apparatus for building pneumatic tyres having a circumferentially inextensible tread reinforcing band, comprises a building drum formed by a cylindrical flexible air-impervious sleeve 20 sealed at its ends to the outer peripheries of two end discs 17, 18 which are mounted for relative axial movement so that, on mutual approach of the discs and inflation of the drum, the sleeve is deformed to shape a flat band carcase 21, wound thereon, into tyre shape with its crown portion engaging an inextensible tread unit 106 centred therearound in a mould ring 107, Fig. 2, the drum having a pair of relatively axially movable beadclamping rings 22, 221 mounted therein which are radially expansible to grip and locate bead rings 23, 23<SP>1</SP> positioned around the carcase plies 75, and the bead rings 23, 23<SP>1</SP> serving to constrain the deformation of the inflated sleeve 20 into three side by side annular portions 108, 105, 109, the outer portions 108, 109 of which are operative to effect turn-over of the carcase ply ends around the bead rings 23, 231. As shown, one end disc 17 is fixedly mounted on a frame member 31 which carries a double acting pneumatic cylinder 11 the piston-rod 16 of which extends axially through the disc 17 and axially adjustably carries the other disc 18 at its free end, selective operation of the piston 15 thereby effecting mutual approach or withdrawal of the discs 17, 18. The sleeve 20 has beaded ends 50, 65 by which it is clamped to the discs 17, 18 and each disc carries also a bowl-shaped baffle member 25, 26 overhanging the adjacent sleeve ends, the baffle 26 being detachably mounted on the disc 18 for assembly of the bead rings 23, 23<SP>1</SP> and eventual removal of the tyre from the drum. The bead clamping rings 22, 22<SP>1</SP> are slidably mounted on the piston rod 16 and have U-section peripheries which mounted annular inflatable tubes 84, 841, the spacing and location of the rings being controlled by tie rods 90, 96 and 100. In operation.-After winding of a carcase band 21 on the cylindrical sleeve 20, the bead rings 23, 23<SP>1</SP> are correctly positioned therearound by means of a spacing member 27 which comprises a pair of parallel arms 80 swingably pivoted on a shaft 28 below the drum for movement to and from a bead ring engaging and spacing position. With the bead rings located, the tubes 84, 84<SP>1</SP> are inflated to expand the carcase ply into gripping engagement with the bead rings, and then the sleeve 20 is inflated, with simultaneous mutual approach of the discs 17, 18 to effect shaping of the carcase. The approach of the discs 17, 18 causes the baffles 25, 26 to deflect the end bulges 108, 109 of the sleeve towards the central sleeve bulge 105, thereby shaping the carcase ply ends, and the chafer strips 78, around the bead rings and stitching them against the shaped carcase. Centring of the tread band mould ring or applicator 107 around the carcase prior to the shaping operation is effected by a carriage 115, on which the applicator 107 is mounted, slidable along a guide rail 129 below the drum and having a pinion 133 in engagement with a pair of parallel racks 135, 136. One of the racks. is slidably mounted relative to the other so that when said other rack stops against the frame member 31, during initial positioning of the applicator, movement of the other rack by a member 142 carried by the end disc 18, on shaping movement of said disc 18, effects final centring of the applicator around the carcase being shaped.